Entropy of a unitary operator on $l^2({\mathbb{N}}_0)$

In this article we continue to study the concept of entropy introduced in [4], [15]-[17]. We calculate entropy for a wider class of finite-dimensional operators in comparison with [15]. We also approximate the entropy of a unitary operator on $l^2({\mathbb{N}}_0)$ by the entropy of finite-dimensional operators. Finally we calculate the entropy of several operators on $l^2({\mathbb{N}}_0)$.